The Mercedes-Benz M-Class is a mid-sizesport utility vehicle (SUV) with light off-road capability, first offered in 1997 as a 1998 model, and built by the German automaker Mercedes-Benz. It marked a shift at Mercedes-Benz in becoming a global player; while it had plants outside Germany before, they merely built German models. Gradually, the M-Class became a sales success in the United States and Mexico. In size, it is slotted below the GL-Class. For a short time, between the years 1999 to 2002, the M class was built by Magna Steyr in Graz, Austria, for the European market, until it moved to part of the U.S. market.

The M-Class was the first luxury SUV to feature stability control, a system designed to detect loss of control and instantaneously intervene with selective braking to bring the vehicle back on its intended course. This system is now hailed by safety experts, and studies have shown stability control and systems like it are capable of reducing single vehicle crashes by up to 30 percent. Furthermore, the M-Class boasted front- and side-impact airbags with advanced occupant detection for the front passenger seat, which, combined with Mercedes' legendary safety structure, earned the M-Class the highest marks in insurance industry crash tests.

A road test on the BBC programme Top Gear revealed that the presenter, Jeremy Clarkson, could put his fingers into the gap below the rear lights and above the rear bumper. This improved over the years, especially after a mild facelift for 2002. However, owners are often unhappy with the car's quality — for example, the car was placed last out of 142 cars in the Top Gear Motoring Survey 2004. DaimlerChrysler spent US$600 million on improvements at the Alabama factory before launching the second-generation ML in 2005.

Before the vehicle was launched, Mercedes-Benz allowed the producers to use two pre-production M-Class SUVs in the film The Lost World: Jurassic Park, and used the vehicle's appearance in the film as a way to advertise it when it was launched. As a result, a Mercedes-Benz ad appears before the film on original VHS copies of the film.

Major model variants have included the ML320, ML350, ML430, ML500, ML550 and ML55, along with the 4-cylinder ML230 and the turbodiesel ML270 CDI and ML400 CDI in Europe. The ML55, or ML55 AMG, featured a V8 engine made by AMG, modified body-work, and other performance features. The ML350 replaced the ML320 as the base model in the United States in 2004, although the ML320 CDI is sold in states where emissions regulations allow.

The current Popemobile is based on a W163 ML430 and has been in service since July 2002.[1] VW had offered to build a new vehicle based on the Touareg, but Pope Benedict XVI opted to continue using his predecessor's Mercedes-Benz-manufactured vehicle.[2]

The redesigned M-class (chassis name W164) was introduced to the public in April 2005 as a 2006 model after showing at the North American International Auto Show in January. It is almost entirely new, with a more sporting, aerodynamic look—the coefficient of drag is down to 0.34. Mercedes-Benz has also made the new M-class larger, measuring 150 mm longer than the first model. The M-Class was named "Best New Sport Utility Vehicle" in the 2006 Canadian Car of the Year awards. The back was commonly referred as a shoebox so DaimlerChrysler spent most of their $600 million dollars on redesigning that part.

Mercedes-Benz extensively publicized the US$600 million that was spent to update their factory and add additional manufacturing space for the new R-Class. According to early automotive press reports, the 2006 M-Class vehicles demonstrate vast improvements in build quality.

The W164 platform used for the new M-Class is shared with the new GL-Class and is a unibody type rather than the former (W163) body-on-frame used by the M-Class vehicles produced from 1998-2005. The X164 GL-CLass, a longer 7-seater version of the W164 platform, is also available.

New features in the 2006 M-Class include the 7G-Tronic seven-speed automatic transmission, optional Active Curve-Illuminating Bi-Xenon headlights which "steer" in the path of the vehicle, and an adjustable-height air suspension. The manual transmission has been dropped.

4-valve engines are replacing the previous 3-valve SOHCV6 and current 3-valve V8:

Models using Bluetec Diesel engine with urea injection will be introduced for the 2009 model year.

ML63 AMG

The AMG version of the W164, the ML63 AMG, was introduced at the 2006 North American International Auto Show as a limited edition 2007 model. It features a 6.2 L M156V8 engine producing 510 hp (380 kW) and 465 lb·ft (630 N·m) that is handcrafted in Germany, which is the most powerful naturally aspirated V8 engine in the world and ever made. The engine is mated to an AMG Speedshift 7G-Tronic seven-speed automatic transmission. The 2006 ML63 AMG can accelerate from 0-60 mph (96km/h) in just 4.8, or from 0-62mph (100km/h) in just 5.0 seconds. These impressive statistics displayed by the ML 63 AMG proclaim it as the fastest and most powerful naturally aspirated V8 engine powered SUV in the world, leaving the 2008 Porsche Cayenne Turbo S in second place.[3]